638663 has 2 divisors, whose sum is σ = 638664. Its totient is φ = 638662.

The previous prime is 638633. The next prime is 638669. The reversal of 638663 is 366836.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 638663 - 2¹² = 634567 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319331 + 319332.

It is an arithmetic number, because the mean of its divisors is an integer number (319332).

2⁶³⁸⁶⁶³ is an apocalyptic number.

638663 is a deficient number, since it is larger than the sum of its proper divisors (1).

638663 is an equidigital number, since it uses as much as digits as its factorization.

638663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 32.

The square root of 638663 is about 799.1639381253. The cubic root of 638663 is about 86.1173357816.

The spelling of 638663 in words is "six hundred thirty-eight thousand, six hundred sixty-three".